The invention discloses an analysis and diagnosis method and device of a centrifugal compressor unit and relates to the technical field of centrifugal compressors. In the running process of the centrifugal compressor unit, analysis and diagnosis can be performed on the centrifugal compressor unit in time. The method includes the steps that in the running process of the centrifugal compressor unit,the running parameter information of the centrifugal compressor unit is acquired in real time; according to the changing tendency of the running parameter information, whether an abnormal condition happens to the centrifugal compressor unit or not is detected; if yes, reason information corresponding to the abnormal condition of running and solution information corresponding to the reason information are inquired from preset storage positions, and reason information corresponding to different abnormal conditions of running and corresponding solution scheme information are stored in the presetstorage positions; and according to relevant information of the abnormal conditions of running and the inquired reason information and solution information, the analysis and diagnosis result of the centrifugal compressor unit is determined.